Periodic Reporting for period 1 - jamclay (Chemical Tools to Probe the Role of Bromodomains in the Parasite Trypanosoma cruzi)
Periodo di rendicontazione: 2016-03-24 al 2018-03-23
Bromodomains are epigenetic reader proteins that bind to acetylated lysine (KAc) residues, these fundamental interactions play a key role in regulation of important transcriptional protein-protein interactions that regulate the expression of certain genes.
Here we report the design, synthesis, and biological evaluation of a range of potent and selective ligands for the CREBBP bromodomain, which is a key transcriptional co-activator.
Objective 1. Our initial hit molecule contained a metabolically unstable dihydroquinoxalinone acetyl-lysine mimicking 'head group' and an aryl amide. The acetyl-lysine mimicking 'head group' was developed into a more metabolically stable benzodiazepinone it's ring expanded head group containing an additional CH2 reduces degradation, as oxidation of dihydroquinoxalinone gives an aromatised quinoxalinone with reduced activity.
Objective 2. Although improving metabolic stability introduction of the benzodiazepinone caused the molecules internal hydrogen bonding network to change, a reduced affinity binding conformation now formed in solution. The internal hydrogen bonding in the presence of the benzodiazepinone head group was a hinderance. Thus we re removed the aryl amide and replaced it with an E-alkene a classical amide bio-isostere.
In order to engage in ligand development we draw information from a number different of techniques including protein and small molecule crystallography, 1H-NMR, waterLOGSY, differential scanning calorimetry (thermal shift) and isothermal calorimetry (ITC).
Furthermore we use a diverse array organic transformations such as β-amino acid synthesis, amidations, hydroborations and Suzuki reactions to stereo-selectively synthesise our target molecules.
Based on the project’s progress we believe that our methods will lead to a significant improvement in the way the field thinks about intramolecular interactions and identifies the presence of hydrogen bonds in their molecules.
Details of the socio-economic impact will be forthcoming following our publication disseminating the results of our investigation and the techniques we used and developed. However it is already clear that the simplicity of our methods lend them selves to adoption as standard procedures for the wider field of medicinal chemistry.